SIM swap or number port fraud: my phone suddenly has no service, what do I do?

SIM swap or number port fraud: my phone suddenly has no service, what do I do?

Your phone has had full signal all day and suddenly shows "No service" or "SOS only". Restarting doesn't help. Your partner's phone, on the same network, works fine. A few minutes later an email arrives saying your bank or email password has been changed. If that sounds like what's happening to you, act now: someone may have taken control of your mobile number, either by getting a replacement SIM or eSIM from your provider, or by porting your number to another telco. With your number, they receive your text codes, and with those, they can get into your bank.

How does SIM swap and port fraud work?

1. They collect your details. Through a fake text or email from your bank, a call pretending to be tech support, or information from data breaches, they get your name, date of birth, address, phone number and sometimes your internet banking login.
2. They pretend to be you to a phone company. With those details, sometimes backed by fake ID, they ask your provider (One NZ, Spark, 2degrees or another) for a replacement SIM or eSIM, claiming the phone was lost or stolen. Or they ask a different provider to port your number across to a new account they control.
3. They use your number to get into your accounts. Once the new SIM is active, yours stops working. Now they receive verification codes by text and can authorise transfers, add your cards to a phone wallet, change passwords or take over your WhatsApp.

What are the warning signs?

• You suddenly lose signal somewhere you always have it, and restarting the phone doesn't fix it.
• You get a text or email about a SIM change, an eSIM activation or a number port you didn't ask for. Treat it as urgent.
• WhatsApp logs you out with a message that your number has been registered on another phone.
• Emails about password resets or new logins for your bank, email or social media that you didn't make.
• Friends say they've had odd messages from "you" asking for money.

What do I do right now?

1. Call your mobile provider from another phone. Use the official number from its website or your bill, never one sent to you by text. Ask whether a replacement SIM, eSIM or number port has been processed on your number. If so, tell them it's fraud and ask them to stop it, restore your number and add extra security (such as an account PIN or port protection).
2. Call your bank on its official number, on the back of your card or on its website. Explain that you suspect someone has hijacked your number and ask them to block internet banking, cards and transfers while it's sorted out.
3. Take back your email. From a computer or tablet on Wi-Fi, change the password of your main email account: it's the key to resetting all your other accounts. Sign out of all sessions and check no forwarding rules have been added.
4. Check your transactions. Log in to internet banking (if you still can) or ask the bank about recent transactions, new cards and authorised devices. Screenshot anything you don't recognise.
5. Warn your contacts. If they've taken your WhatsApp, they may ask your family for money pretending to be you. A message from another account or a phone call is enough: "My number has been stolen, if I message you asking for money, it's not me."
6. Keep the evidence. Note the time you lost service, screenshot the alert texts and emails, and write down the names of the people you spoke to at your provider and bank.

Don't wait to "see if the signal comes back". Every minute the criminal controls your number is a minute they can receive your codes.

What if money has already been taken?

1. Ask your bank to treat the transactions as unauthorised and to investigate and refund them. Put it in writing as well, and keep the reference number. The sooner you report it, the better.
2. Report it to Police on 105 or through the 105 online service on the NZ Police website. Include the time you lost service, the provider's confirmation of the SIM swap or port, and the bank transactions.
3. Report it to the National Cyber Security Centre through the NCSC, especially if your email or other online accounts were taken over.
4. Complain to your mobile provider for allowing the swap or port without properly checking your identity. Ask in writing when, where and how it was requested. If its complaints process doesn't resolve things, you can take it to Telecommunications Dispute Resolution (TDR), the free scheme for unresolved telco complaints.
5. Get identity support. IDCARE, a not-for-profit identity and cyber support service, can help you work out what else might be exposed and how to lock it down.

How do I stop it happening again?

• Avoid text messages as your second factor when there's an alternative: an authenticator app or a security key doesn't depend on your SIM.
• Ask your provider about extra account security, such as an account PIN, password or port protection, so nobody can swap your SIM or move your number without an extra check.
• Set a SIM PIN on your phone.
• Never share personal details or codes by phone or text, even if it looks like your bank or telco. If in doubt, hang up and call the official number yourself.
• Turn on notifications from your bank and email so you hear about any change straight away.

Frequently asked questions

Could it just be a network outage? Possibly. Check whether others on the same network nearby have service, or look at your provider's outage page from another device. If you also get emails about password changes or a SIM change you didn't make, treat it as fraud.

Will I get my number back? Yes. Your provider can reverse a fraudulent swap or port and give your number back to you. The faster you call, the faster it's done.

I have an eSIM. Can this happen to me too? Yes. An eSIM can be moved to another device in the same way. The same steps apply.

What about WhatsApp? Once your number is back, register WhatsApp again on your phone and turn on two-step verification so nobody can take it over again.

In short

A sudden "No service" plus alerts you don't recognise means act now: call your provider from another phone, call your bank, secure your email and warn your contacts. If money was taken, report it to your bank, Police and the NCSC, and complain to your provider, escalating to TDR if needed. And report any suspicious calls or texts you received beforehand in the NoCall spam numbers directory.